Personal injury lawyers like Steven Cahn can produce enough paper in a year to cause the death of vast forests, but Cahn has made amends.

He and his firm, Edison's Cahn & Parra, donated $75,000 worth of pro bono work and won a federal suit that stopped a pipeline company from cutting down 80 trees and destroying the leafy ambiance of a neighborhood in Piscataway.

Cahn did it because he represents the neighborhood on the town council. Plus, it was a rewarding intellectual exercise, he says. And the outcome may guide other towns about how to win environmental disputes with pipeline companies, he says.

Duke Energy Operating Co. and Texas Eastern Transmission, both of Houston, argued that tree roots could harm three pipelines in town and that leaf-covered branches towering up to 75 feet were preventing aerial observation vital to the security of the right of way. They claimed that easements on the neighboring properties gave them a right to remove.

But on Sept. 20, U.S. District Judge Faith Hochberg in Newark granted summary judgment to the residents represented by Cahn. The defendants could not exercise their easements because they had failed to prove the tree-cutting was necessary. "There must be real facts to support the safety argument," Hochberg concluded in Township of Piscataway v. Duke Energy, 08-4828.

The companies disclosed the tree cutting operation in April 2000 and the town stopped it with a preliminary injunction in October 2001. But by March 2003 the town decided it could no longer afford the fight on the merits and agreed to a Solomonic settlement. The defendants reimbursed the town for its fees and said they would cut down 55 trees, leaving the 25 remaining, smaller trees until they grew to eight inches in diameter or more.

"We were trying to fight the good fight, but the costs were prohibitive," Mayor Brian Wahler says. Towns can't afford litigation with huge operations, particularly pipeline companies that are afraid a legal loss in one locale will set a national precedent, he says. "They will fight anywhere, anytime to protect their turf," Wahler says.

Fees had reached the $50,000 mark and the town "didn't want to pay $50,000 to save a single street," Cahn says.

So he and partner Harold Parra stepped in as counsel to the homeowners who remained as plaintiffs. As councilman, Cahn had cheered the town's efforts for his constituents. Now he was cheerleader and quarterback, too.

Cahn is a Democrat in a Democratic town. "I have a pretty safe district. I didn't have to do it to win re-election and I'm not running for president." He says.

Doing work other than the firm's normal personal injury and employment practice was a pleasure, he says.

"At one point Harold and I were joking, 'Isn't this fun, we're learning more about property law and easements that we have since law school'."

It was all about the easements. The pipelines, two built after the town granted an easement in 1944 and a third after a 1980 grant, were on open land until homes were built alongside the right of way. The spruce, beech, maple and London plane trees were planted when the homes were built in the 1960s.

In the 40 years that followed, the trees hadn't reached the epic stature of the majestic oak down the road in New Brunswick said to have inspired Joyce Kilmer to write "Trees."

But they were big enough to give great pleasure to their owners and heartburn to the pipeline companies, which use aerial surveillance to spot leaks. The pipes are underground, but damage to the vegetation above can be seen from the air and is a telltale sign of trouble. The companies also fear pipe-eating roots.

Hochberg found, however, that the companies hadn't shown there had been any damage and that on-site inspections were a viable alternative to aerial surveillance. That, in effect, tipped the balance in favor of the trees. "As the trees are decades old, they are eventually irreplaceable," she found.

She also said the companies' wait of 40 years to exercise their rights was inexcusable and prejudicial.

It's not clear whether the ruling breaks new legal ground.

Defense lawyer Edwin Landis Jr. of Newark's Meyner and Landis says the case generated a huge record of facts that make the ruling inexplicable to other situations. He says the defendants haven't decided whether to appeal. He says another option could be to gain control of the tree property by invoking eminent domain law.

Town attorney James Clarkin III says, on the other hand, that the Piscataway easements are typical of those around the country. If Duke Energy and Texas Eastern can't invoke them to knock down trees in Piscataway, they may not be able to do it elsewhere, he says.

Clarkin says he bet Cahn a bottle of fancy wine the pipeline companies would win, and he's glad he lost the bet. With an appeal possible, the pro bono effort may become a marathon and Cahn's wine is at risk. "I may go double or nothing," Clarkin jokes.